Spring-balance scale.



A. N. UZIAS, DEGD.

D, L. PAIRGHILD 6 R. MN L', IIAXBY, ADMINIs'rM-LTOM SPRXNG BALANCE SCALE.

APPLIUATION FILED JULY 3,1912.

"illustrative 4purposes' is primarily ,To all 'whom it may concern UNITED STATES PATENT tiraron,

ALBERT N.OZIA.S, .'IDIElCEASlDz LATE OF MINNEAEOLIS, MINNESOTA, DAVID L. 'FAIBGHILD AND ROBERT VAN LOAN H AXBY, ADMINESPRATOBS, 'OF MINNEAP- OLIS, MINNESOTA.

, SPRING-BALANCE SCALE.

Specicaton of Letters Patent.

Patented Ann "2', 1914,

Be itkn'own that vALrnrr N. Oznas, deceased, late a citizen of the United' States residing at Minneapolis, in the county of Hennepin and State of Minnesota, did invent certain new and useful Improvements in Spring-Balance Scales, of which the tollowing is a full, clear, and exactdescription, reference drawings,.orming part of this specification, and to the figures and letters of reference marked thereon.

This invention relates to scales of that type in which the load is counterbalanced by a, spring or springs, one object of the ini, J ution being to-provide a construction in which. the eectof variations in temperature on the counterbalancing mechanism will be neutralized or overcome automatically and 'the scales caused to givel a correct indication of weight at any prevailing temperature.

' Another object of the invention is to provide 'a mechanism which will autdmatically compensate for or neutralize the variations due to temperature changes throughout a wider range of temperatures than has heretofore' been deemed practical and to sim- A plify and clieapen the cost of the mechanism whereby the invention may. beA applied to scales for opular-use without materially increasing tliie cost of the same.- i

the form adopted for.

-'The invention in adapted for use in connection with so-called computing or price scales, and referring. to the accompanying drawings, Figure 1 is a front` elevation of a price scale having-thc present invention embodied therein, portions of the structure bein broken away to show underl ing'parts; tig. 2 is a perspective View of tiie preferred form of controlling or compensatin mechanism; and Fig. 3 is a cross section t rough the part. of the device illustrated in Fig.` 2, and which, as a wholev` is commonly designated a hook bar.

Like letters of reference in the several ligures indicate the same parts.

Generally speaking, the scalo illustrated is one of a Well known type now in extensive being had to the accompanying -formcd of a metal with a public use and embodies in its construction a casing A within which there-is journaled a drum having' upon its periphery lsuitable indications of value and weight lwhich are displayed through a sight opening in the casing. At each end of the casing counterbala-ncing springs C of the usual. coil tension type are suspended, and inr turn are connected at their lower ends with the bottoni bar or member, commonly designated as the hook bar. In accordance with the present invention, this hook bar is a compound member embodying a tension member E to an intermedia-te portion of which the hook or load support F is connected in any suitable manner and said load support or hook is, through the frame G, transverse rod H and rack bars i meshing with pinionsl on the ends of the drum, adapted to rotate the drum in' proportion to the downward movement oi'- the load support. The tension member E constitutes in ei'i'ect a portion .of the counterbalancing springs and will be defiected centrally in proportion to the weight of the load carried by the load support. it is preferably 'of .tempered metal and, oi' course, roughly proportioned to the capacity of the scale, but its deflection is in the present instance adapted to becontrovlled and regulated in accordance with theyprevailing temperature by a thermostatic member formed of metal having different co-eiicients of expansion, and so assembled and connected theren-'itli that upon a rise in temperature the member E will be put under increased tension, thereby increasing its resistance to deiiection, and so neutralizing the eii'ect oi the rise in temperature upon the action of the main counterbalancing springs C. As illustrated, the ends of the member E are anchored in blocks or cap pieces H preferably by adjusting nuts h, and these end or cap pieces H also serve as the anchors tor the opposite ends ol an arc-shaped iii-metallic ilicrniostat menilier K preferably having' its concave side high co-elicient oi expansion and its convex side of a metal with a low co-efiicient of expansion. Conveniently, the member is formed by iirmly member, they are connecting, as by rivets, at frequent inter' ,in place by screws L, although it willbe creasing as the temperature lowers, due to understood that the particular connecting arrangement between the ends' 'oi' the b1- metallic and tension member E is not particularly important, if care be taken to make the connection suiiciently rigid to prevent any looseness between the parts such as will cause an irregularity in the action of the scale. i

In assembling the mechanism, it is preferred that the member E which may be conveniently termed a-chord member be substantially straight and under'"considerable initial tension, while the lai-metallic or thermostatic member is preferably bowed to a considerable extent. Vith this construction, the practical result is that the chord member has its tension varied in accordance with the variations in temperature, such tension increasing as the temperature rises and dethe fact that the metalhaving a high cooiicient of expansion tends tostraighten the arc-shaped bi-metallic member as the temperature rises, but inasmuch as no straightlening can occur, owing to the ends of the bi-mctallic member being anchored to the chord member, the result is to greatly increase the tension of the chord member and the range of vvariation in temperature through 'which the device iwiil operate to effectually neutralize the variation inthe action of the main counterbalancing spring is greatly increased.

Not only does the device respond quickly to changes in temperature, but it adapts itseli to the load being vweighed and is not liable to become set or strained by an overload; thus 1t may be used on scales of large capacity, without danger of destroying their accuracy for weighing in small increments.

Having thus described the invention what is claimed'as new is: A 'i l. In' a scale, the combination with counterba'la'ncing spring tension member, 'an indicator, anda load support connected with the indicator and with thespring tension member intermediate'it's ends, of a curved bi-metallic thermostat member 'having its ends rigidly connected with the ends oi? said sprin tension member to increase the longitudinal tension of said tension member ,andj-itsresistance to deflection as fthe tem- .ipeature 2. In a scale2 the combination with indicating mechanism, la load support operatively connected with the indicating mechanism and a countcrbalancing spring tension member adapted to be deflected transversely by the load, of a curved bi-metall-ic member anchored at 'its ends to the lends of the to be deiected transversely intermediate its ends, of a curved' loi-metallic member anchored at its end to the ends of the counterbalancing spring tension member, said bimetallic member bein formed of metals having different co-e cients of expansionv with the metal having the higher 'co-eiiicient of expansion on the concave side, whereby the counterbalancing spring tension member is put under increased longitudinal tension as the temperature rises.

system embodying co'il springs .and a fi. 'In a scale, the combination with indi- 'eating mechanism, a counterbalancing springstraight tension member spring and a load support carried by the tension member intermediate its ends and operatively con-` nected with the indicating mechanism, of a curved bi-inetallic thermostat bar rigidly connected at opposite lends with opposite ends of the tension member,l the metal of ,the thermostat bar having the higher co-A eicient of expansion being located on the i concave side of the bar.

5. In a spring balance scale, the combination with two suspended coiil springs and an indicator, of a hook bar suspended from said coil springs and embodying a substantially straight tension member and a curved i bi-metallic member formed of metals having different co-eiiicients of expansion, a load support carried bysaid tension member inter-mediate its ends and connections intermediate the load support and indicator.

6. In a spring balance scale, "the coml bination of, an indicator,"counterbalance springs and a hook bar suspended from said' 4 springs and embodying a delectable chord member, an arc-shaped bi-met'allic member rigidly connected at its ends' with the ends v lof chord member', vand av load suport carried by'dthe chord'membe'r 'inte 'ate its end s with 'connections,.intermediate the j load support 'and' indicator.

7. in a .spring balancevscale, 4the comsind with the metal having the higher c0- iiicieut. of expanmon ou Athe concave Side.

DAV ID L. FA] RCHLD. RBERT VAN LOAN HAXBY.

Acl/nbm'stmtws of the' estate of Albert N.

Oz'icis, deceased. W it mossos JOHN CBENSON, li. (i. MACKALL. 

